Tilting multiplier

ABSTRACT

A method of operating a tilting carrier assembly includes operating a conveyor in a primary direction of travel and supporting a work piece from the conveyor by a pair of links. A pair of respective upper connection points of the links are laterally spaced transverse to the primary direction of travel and a pair of respective lower connection points of the links are also laterally spaced. The work piece is conveyed along the primary direction of travel relative to a work station, and the upper connection points are tilted so that a line therebetween forms a first angle relative to horizontal. In response, the lower connection points and the work piece are tilted to a second angle relative to horizontal, and the second angle is greater than the first angle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/697,237, filed Apr. 27, 2015, now U.S. Pat. No. 9,409,730 which is acontinuation of U.S. patent application Ser. No. 13/829,446, filed Mar.14, 2013, now U.S. Pat. No. 9,016,464 which claims priority to U.S.Provisional Patent Application No. 61/620,155, filed Apr. 4, 2012, theentire contents of all of which are incorporated by reference herein.

BACKGROUND

The present invention relates to finishing systems and processes formanufactured parts, and more particularly to carriers for transportingmanufactured parts through a finishing process and methods relating tothe same. For example, a finishing process can include an electroplatingprocess whereby manufactured parts are immersed in one or a sequentialplurality of fluids. The shape of complex parts (e.g., automotivebodies) can introduce difficulty in ensuring full coverage of the parts(via elimination of trapped air), and also drainage of fluid from theparts after removal from a dip tank. Typically, surface coverage maysuffer, or very complex and costly machines must be utilized to ensuregood coverage of and drainage from complex parts. One such machine isdescribed in U.S. Pat. No. 4,772,374, the entire contents of which arehereby incorporated by reference. This patent also describes some of theadvantages of eliminating trapped air during electrodeposition orelectropainting processes, and draining fluid from parts upon removalfrom a dip tank, by tilting the parts.

SUMMARY

In one aspect, the invention provides a tilting carrier assembly for afinishing process. The tilting carrier assembly includes a load barconfigured to convey a work piece relative to a work station. A skid isconfigured to receive the work piece. Each of a pair of links ispivotally coupled to the load bar at a first end and pivotally coupledto the skid at an opposite second end. A horizontal span between thefirst ends of the pair of links is substantially greater than ahorizontal span between the second ends of the pair of links.

In another aspect, the invention provides a tilting carrier assembly.The tilting carrier assembly includes a load bar configured to convey awork piece relative to a work station. A skid is configured to receivethe work piece. Each of a pair of links is pivotally coupled to the loadbar at a first end and pivotally coupled to the skid at an oppositesecond end. The pair of links is configured so that tilting of the loadbar to a first angle relative to horizontal results in tilting of theskid to a second angle relative to horizontal, the second angle being atleast 50 percent greater than the first angle.

In yet another aspect, the invention provides a tilting carrierassembly. The tilting carrier assembly includes a load bar configured toconvey a work piece relative to a work station. A skid is configured toreceive the work piece. Each of a pair of links is pivotally coupled tothe load bar at a first end and pivotally coupled to the skid at anopposite second end. The skid is responsive to tilt relative tohorizontal by an amount greater than the load bar, solely by the forceof gravity, in response to tilting of the load bar relative tohorizontal.

In yet another aspect, the invention provides a tilting carrierassembly. The tilting carrier assembly includes a load bar configured toconvey a work piece relative to a work station. A skid is configured toreceive the work piece. Each of a pair of links is coupled to the loadbar at a first end and coupled to the skid at an opposite second end. Ahorizontal spacing between the second ends of the pair of linksdecreases at an accelerated rate compared to a decrease in a horizontalspacing between the first ends of the links when the load bar is tilted.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a tilting carrier assembly according to oneaspect of the invention.

FIG. 2 is a side view of a treatment system for conveying a plurality oftilting carrier assemblies between a plurality of work stations, one ofthe tilting carrier assemblies being immersed and tilted at one of thework stations.

FIG. 3 is a side view of the treatment system of FIG. 2, one of thetilting carrier assemblies being removed from and tilted above one ofthe work stations.

FIG. 4 illustrates a treatment system similar to FIGS. 2 and 3, havingan alternate orientation with respect to a primary direction of travel,which is into or out of the page as viewed in FIG. 4.

FIG. 5 illustrates the tilting carrier assembly of FIG. 4 immersed in atank and tilted at the work station.

FIG. 6 illustrates the tilting carrier assembly of FIGS. 4 and 5 liftedfrom the tank at the work station.

FIG. 7 illustrates the tilting carrier assembly of FIGS. 4-6 tiltedabove the tank at the work station.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

A tilting carrier assembly 20 is illustrated in FIG. 1. The tiltingcarrier assembly 20 includes a primary carrier or load bar 24 configuredto be transported between a plurality of work stations 28 by a conveyor32 (FIGS. 2 and 3) as part of a conveyor system, as described in furtherdetail below. The conveyor 32 can define a primary direction of travelA, which is substantially horizontal in the illustrated construction.The load bar 24 can be a rigid structure having a first end 24A and asecond end 24B opposite the first end 24A. The load bar 24 can becoupled to the conveyor 32 at a first coupling 36A adjacent the firstend 24A and a second coupling 36B adjacent the second end 24B. The firstand second couplings 36A, 36B can be spaced along the primary directionof travel A to constitute forward and rearward couplings. However, thefirst and second couplings 36A, 36B can be positioned side by side at acommon position along the primary direction of travel A as shown inFIGS. 4-7, or at a skewed orientation with respect to the primarydirection of travel A.

A work piece support or skid 40 is provided below the load bar 24,supported by the load bar 24 as a secondary carrier. A work piece 44 issupported by the skid 40 in fixed relationship therewith. The work piece44 can be coupled to the skid 40 in any one of a number of differentmanners. Also, the work piece 44 can be coupled to any one of a top,bottom, or side of the skid 40, and can be directly or indirectlyfastened to the skid 40. In the illustrated construction, the work piece44 is supported directly on top of the skid 40. Regardless of the mannerof fastening, the work piece 44 moves with the skid 40 (i.e., when theskid 40 is conveyed or tilted, the work piece 44 is conveyed or tiltedthe same amount). However, as will be described in greater detail below,the skid 40 and the work piece 44 are configured to tilt to an amplifieddegree in response to tilting of the load bar 24.

The skid 40 is supported below the load bar 24 by a pair of links,including a first link 48A and a second link 48B. As illustrated, thefirst link 48A is a forward link and the second link 48B is a rearwardlink. Each of the links 48A, 48B is coupled at an upper end to the loadbar 24 and at a lower end to the skid 40. The links 48A, 48B can bepivotally coupled to both the load bar 24 and the skid 40 (e.g., withpivot pins, bearings, etc.). The links 48A, 48B can be rigid members,such as beams, rods, poles, shafts, or bars, in some constructions.However, in other constructions, the links 48A, 48B can be flexiblemembers such as chains, cables, ropes, etc. In such constructions, theattachment points of the links 48A, 48B to the load bar 24 and the skid40 can be but need not be provided with special pivoting hardware, sincethe links 48A, 48B can pivot naturally adjacent the connection points byvirtue of their flexure or other movement to define pivotal couplings orattachment points. Whether the links 48A, 48B are rigid or non-rigid,the skid 40 is configured to hang from the load bar 24 via the links48A, 48B, which together with the load bar 24 and the skid 40, candefine a four-bar linkage. It will be appreciated that the illustratedset of links 48A, 48B can be a first set of links and that asubstantially identical second set of links 48A, 48B can be provided onan opposite side of the tilting carrier assembly 20. On the other hand,if the links 48A, 48B are of suitable rigidity, and the connectionpoints are of suitably robust for the intended loads, the tiltingcarrier assembly 20 may only be provided with a single set of links 48A,48B located on either side, the middle, or other location on the tiltingcarrier assembly 20.

As shown in FIG. 1, a length L₁ between the upper connection points ofthe first and second links 48A, 48B is substantially larger than alength L₂ between the lower connection points of the first and secondlinks 48A, 48B. In some constructions, the length L₂ between the lowerconnection points of the first and second links 48A, 48B is 70 percentor less than the length L₁ between the upper connection points of thefirst and second links 48A, 48B. In some constructions, the length L₂between the lower connection points of the first and second links 48A,48B is 50 percent or less than the length L₁ between the upperconnection points of the first and second links 48A, 48B. In theillustrated construction, the length L₂ between the lower connectionpoints of the first and second links 48A, 48B is between about 40percent and about 55 percent of the length L₁ between the upperconnection points of the first and second links 48A, 48B.

The load bar 24 can be one or more beams, bars, rods, tubes, plates,combination thereof, or other type of structure of either solid orhollow construction that is configured to maintain the attachment pointsof the upper ends of the links 48A, 48B at the fixed length L₁.Likewise, the skid 40 can take any one of a plethora of different formsand constructions that maintain the attachment points of the lower endsof the links 48A, 48B at the fixed length L₂. By non-limiting example,the skid 40 can include a frame, platform, fixture, bucket, basket, orbarrel.

In the illustrated construction, the links 48A, 48B are of substantiallyequal length. Thus, the linkage formed by the load bar 24, the links48A, 48B, and the skid 40 is shaped as a downwardly-tapered isoscelestrapezoid when the load bar 24 is in a horizontal orientation. In otherembodiments, however, the links 48A, 48B may have different lengths thatcan generate a tilted orientation of the skid 40 with respect to theload bar 24 in one or more orientations of the load bar 24 (e.g.,horizontal or tilted orientations). The links 48A, 48B are also centeredfront-to-back along the load bar 24 and the skid 40, although otherconfigurations are optional.

Due to the configuration of the linkage, the skid 40 and the work piece44 are configured to tilt passively, solely by the force of gravitywithout another drive force, to a greater degree than the load bar 24,when the load bar 24 is tilted relative to horizontal. The mechanismtakes advantage of the short length L₂ between the attachment points ofthe links 48A, 48B on the skid 40, which allows the combined center ofgravity of the skid 40 and the work piece 44 to promote greater tiltingof the skid 40 in relation to horizontal as compared to that of the loadbar 24. In fact, the skid 40 and the work piece 44 can tilt to an angleβ with respect to horizontal that is at least 50 percent more than theload bar 24 when the load bar 24 is tilted to an angle α with respect tohorizontal. In some constructions, the skid 40 and the work piece 44 cantilt at least 20 percent more than the load bar 24 when the load bar 24is tilted. Also, in some constructions, the skid 40 and the work piece44 can tilt at least 50 percent more than the load bar 24 when the loadbar 24 is tilted. In still other constructions, the skid 40 and the workpiece 44 can tilt at least 100 percent more (twice the angular tilt)when the load bar 24 is tilted. In the illustrated construction, theangle β of tilt of the skid 40 and the work piece 44 can be up to 2.5times the angle α of tilt of the load bar 24 (e.g., 20 degrees versus 8degrees). During tilting, the horizontal spacing between the attachmentpoints of the links 48A, 48B on the skid 40 decreases at an acceleratedrate compared to a decrease in a horizontal spacing between theattachment points of the links 48A, 48B on the load bar 24. Theamplified tilting of the skid 40 and the work piece 44 allows much moreclearance or freedom of space around the load bar 24 and requires lessvertical driving input from the conveyor 32 to achieve a particularamount of tilt of the work piece 44.

FIGS. 2 and 3 illustrate a conveyor system including a plurality oftilting carrier assemblies 20, each movable along the primary directionof travel A by the conveyor 32 between the plurality of work stations28. The conveyor 32 can be part of any overhead conveyor system, such asthe systems disclosed in U.S. Pat. No. 4,942,956 and U.S. Pat. No.5,012,918. Further, the conveyor system can be adapted accordingly so itmoves in any suitable direction. The work stations 28 can includefinishing stations, such as electrocoating immersion tanks forsubmerging the work piece 44 into an electrocoating liquid. However, thework stations 28 can also include other types of equipment, such as anoven or drying station, a paint spray station, and the like. At one ormore of the work stations 28, it may be desirable to tilt the work piece44 to enhance the finish quality. For example, tilting of the work piece44 while immersed in an electrocoating bath (FIG. 2) promotes full andeven coverage, and tilting of the work piece 44 after removal from thebath (FIG. 3) promotes full drainage.

A process of conveying one or more work pieces 44 through a finishingprocess can include the following steps. First, the work piece 44 issecured to the skid 40. The conveyor 32 is operated to transport thework piece 44 to a work station 28. The conveyor 32 may transport thework piece 44 directly into the work station 28 along the primarydirection of travel A, or may first transport the work piece 44 to aposition above the work station 28 (e.g., in the case of an immersiontank holding an electrocoating liquid). A vertical drive may lower thetilting carrier assembly 20 from the conveyor 32 so that the work piece44 is lowered into the work station 28. The vertical drive can includeany suitable system for producing the required vertical travel.Alternately, the conveyor 32 may follow a path that descends to allowthe work piece 44 to descend into the work station 28. The work piece 44can be lowered while traveling along the conveyor 32 or after stoppingat a position along the conveyor 32 corresponding to the desired workstation 28. While in the work station 28, the load bar 24 is tilted apredetermined amount with respect to horizontal, and the skid 40 andwork piece 44 are tilted passively by an amount substantially greaterthan the load bar 24. The load bar 24 can be tilted by unequal verticalmovement of the first and second couplings 36A, 36B, in any combinationof upward and downward movement, or moving one of the couplings 36A, 36Bwhile holding the other at a fixed height. Any suitable device (e.g.,one or more cranes or winches, hydraulic or pneumatic pistons, changesin conveyor elevation on different sides and/or at different locationsalong the conveyor 32, etc.) may be utilized to obtain the tilt of theload bar 24. The tilting process may be repeated as desired within thework station 28, before the work piece 44 is moved out of the workstation 28 (e.g., lifted out of an immersion tank). In some cases, theload bar 24 may be tilted one or more times after removal from the workstation 28 (e.g., above an immersion tank to drain liquid from the workpiece 44). The work piece 44 is then transported via the conveyor 32 toanother work station 28 or to an unloading area of the conveyor system.

The system and method described herein are applicable for any number ofwork stations 28. In some constructions, the work piece support(referred to herein as the skid 40) may carry more than one work piece.In some such constructions, the one or more work pieces may not beimmovably secured to the work piece support to tilt in fixedrelationship therewith, but it still may be desirable to produceamplified tilting of the work piece support.

Various features and advantages of the invention are set forth in thefollowing claims.

What is claimed is:
 1. A method of operating a tilting carrier assembly,the method comprising: operating a conveyor in a primary direction oftravel; supporting a work piece from the conveyor by a pair of links,wherein a pair of respective upper connection points of the pair oflinks are laterally spaced transverse to the primary direction of traveland a pair of respective lower connection points of the pair of linksare laterally spaced transverse to the primary direction of travel;conveying the work piece along the primary direction of travel relativeto a work station; tilting the upper connection points so that a linetherebetween forms a first angle relative to horizontal; and in responseto the tilting of the upper connection points to form the first angle,tilting the lower connection points and the work piece to a second anglerelative to horizontal, the second angle being greater than the firstangle.
 2. The method of claim 1, wherein the second angle is at least 50percent greater than the first angle.
 3. The method of claim 1, whereinthe second angle is at least twice the first angle.
 4. The method ofclaim 1, wherein the second angle is about 2.5 times the first angle. 5.The method of claim 1, wherein the lower connection points areresponsive to tilt solely by the force gravity when the upper connectionpoints are tilted relative to horizontal.
 6. The method of claim 1,further comprising conveying the work piece to at least one additionalwork station.
 7. The method of claim 1, further comprising lowering thework piece into the work station.
 8. The method of claim 7, furthercomprising electrocoating the work piece within an immersion tank of thework station.
 9. The method of claim 7, further comprising lifting thework piece from the work station and further tilting the upperconnection points while the work piece is positioned above the workstation.
 10. The method of claim 1, further comprising lowering the workpiece into a paint spray station of the work station.
 11. A method ofoperating a tilting carrier assembly, the method comprising: operating aconveyor in a primary direction of travel; supporting a work piece fromthe conveyor by a pair of links, wherein a pair of respective upperconnection points of the pair of links are spaced apart by a firstlength and a pair of respective lower connection points of the pair oflinks are spaced apart by a second length that is less than the firstlength; conveying the work piece along the primary direction of travelrelative to a work station; lowering the work piece into the workstation; tilting the pair of upper connection points so that a linetherebetween forms a first angle relative to horizontal while the workpiece is in the work station; in response to the tilting the upperconnection points to form the first angle, tilting the lower connectionpoints and the work piece to a second angle relative to horizontal, thesecond angle being greater than the first angle; lifting the work piecefrom the work station; and after lifting the work piece from the workstation, tilting the pair of upper connection points while the workpiece is positioned above the work station.
 12. The method of claim 11,wherein the second angle is at least 50 percent greater than the firstangle.
 13. The method of claim 11, wherein the second angle is at leasttwice the first angle.
 14. The method of claim 11, wherein the secondangle is about 2.5 times the first angle.
 15. The method of claim 11,wherein the lower connection points are responsive to tilt solely by theforce gravity when the upper connection points are tilted relative tohorizontal.
 16. The method of claim 11, further comprising conveying thework piece to at least one additional work station.
 17. The method ofclaim 11, wherein lowering the work piece into the work station includeslowering the work piece into an immersion tank.
 18. The method of claim17, further comprising electrocoating the work piece within theimmersion tank.
 19. The method of claim 11, further comprisingun-tilting and re-tilting the upper connection points relative tohorizontal while the work piece is in the work station.
 20. The methodof claim 11, wherein lowering the work piece into the work stationincludes lowering the work piece into a paint spray station.
 21. Amethod of operating a tilting carrier assembly, the method comprising:operating a conveyor in a primary direction of travel; conveying a workpiece along the primary direction of travel, wherein the work piece issupported by the conveyor with a pair of links that are laterally spacedtransverse to the primary direction of travel, each of the pair of linkshaving an upper connection point at a first end and a lower connectionpoint at an opposite second end coupled to the work piece; tilting theupper connection points while maintaining a fixed first lengththerebetween to decrease a horizontal spacing between the upperconnection points of the pair of links; and decreasing a horizontalspacing between the lower connection points of the pair of links at anaccelerated rate compared to the decrease in a horizontal spacingbetween the upper connection points of the pair of links as the upperconnection points are tilted.